Process Safety and Environmental Protection, Vol.109, 716-731, 2017
The development and testing of a novel external-spraying injection dedusting device for the heading machine in a fully-mechanized excavation face
This paper discusses the development of a novel external-spraying injection dedusting device, which has the potential to reduce substantially the amount of dust produced by a heading machine during the cutting process in a fully-mechanized coal face. Firstly, the migration rules of the inner wind flow field are analyzed using numerical simulations, and then the atomization function of the spraying nozzle is optimized. Consequently, the nozzle exhibited the highest airborne dust reduction rate at a spraying pressure of 4 MPa. The proposed device's functionality was also tested by experiments, with the results indicating that as the spraying pressure increased from 2 MPa to 8 MPa, the gas liquid ratio increased at first and then decreased, reaching a maximum of 1.269 at a spraying pressure of 4 MPa, which was subsequently once again selected as the optimal spraying pressure. Finally, field experiments were conducted on the developed dedusting device, with the results showing that, compared with the original spraying dust reduction method, when the developed external spraying injection dedusting device was opened, using the dust reduction method (d), the average dust reduction rates of the total coal and respirable dust are enhanced by 17.0% and 18.3% respectively; moreover, using the dust reduction method (c), the average dust reduction rates of total coal and respirable dust are enhanced by 11.6% and 12.0% respectively. Therefore, it can be calculated that by using the injection dedusting method, the average reduction rates are enhanced by 5.4% and 6.3% respectively. In particular, the use of one of the proposed dust removal methods at the measuring point where the machine's driver is located, led to the average concentrations of total dust and respirable dust decreasing from 305.1 mg/m(3) and 129.5 mg/m(3) to 88.2 mg/m(3) and 38.3 mg/m(3) respectively. (C) 2017 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.